POCUS (abdomen, pleural, cardio) Flashcards
What is the difference between FAST and POCUS?
FAST: focused assessment with sonography for trauma
- developed to detect pathology in trauma patients (abdominal + thoracic) [free abdominal fluid]
- not for non-trauma patients
POCUS: point-of-care ultrasound
- answering a focused question(s) by a clinician rather than assessing all structures by a specialist
- for all patients, more things we can do
- moved towards this to mirror human med
What is the value of answering binary clinical questions with POCUS?
likelihood of false negative and false positive results markedly decrease when asking binary questions
avoid fishing expeditions!
stable patients have a _____ chance of having free fluid. unstable patients have a ______ chance of having free fluid.
<10%
≥75%
What are the 5-point APOCUS binary questions?
- is there free abdominal fluid?
- is there gall bladder wall edema?
- Is there pericardial effusion?
- is there pleural effusion?
- urine production? (vol estimation)
why should you avoid dorsal when ultra sounding a patient?
bad for resp distress (can’t breath)
bad for CV compromised (bc abdominal organs compress CaVC which compromises venous return)
tell me the 3 big general applications of POCUS
- abdominal pocus
- pleural space and lung ultrasound (PLUS)
- Cardiac POCUS
what are the 5 T’s of pOCUS? basically what is POCUS used for?
Trauma, Triage, Treatment, Tracking, Total
to answer the question “Is there free abdominal fluid?”, what sites do we look at? what are the target organs?
AKA what are the 4 sites of the original abdominal POCUS study PLUS the new 5th view??
- subxiphoid –> liver, spleen, gall bladder, diaphragm
- urinary bladder –> urinary bladder + body wall
- right paralumbar –> liver, R kidney, intestines
- left paralumbar –> tail of spleen, L kidney, intestines
- umbilical –> ???
when scanning the urinary bladder on US, where does fluid often accumulate?
- between bladder and ventral body wall
- apex of bladder
- gravity dependent (??)
true or false:
individual liver lobes should be discernible on US
FALSE!!! individual liver lobes should NEVER be discernible on US!
what does free fluid look like on US?
anechoic, forming sharp angles (uncontained)
You perform an abdominal POCUS and determine that there is free fluid. what should you do next?
abdominocentesis to figure out what kind of fluid it is
when should you do serial abdominal POCUS’s?
recommended in all patients if cause is uncertain.
repeat on as needed basis
- repeat if unstable and cause is unknown
- repeat if pt changes from stable to unstable and cause is unknown
- repeat following therapy if cause is unknown
why is abdominal POCUS limited?
negative POCUs doesn’t rule out injury
doesn’t assess all sites of abdomen
doesn’t assess all organs
doesn’t assess all possible ddx’s
How do you estimate bladder volume?
W x L x (DL+DT)/2 x0.52 (measured in cm, est. in mL)
W= horizontal line from one end of bladder to the other in transverse view
L= horizontal line from one end of bladder to the other in longitudinal view
DL= vertical line from top to bottom of bladder in longitudinal view
DT= vertical line from top to bottom of bladder in transverse view
how do you answer the question “is there gall bladder wall edema?”?
subxiphoid site for US
look for “halo sign” around gall bladder –> you’ll see the anechoic gall bladder, then a white line, then a ring of anechoic fluid, then white again –> literally a halo around the gall bladder
what are 4 ddx for gall bladder wall thickening/edema?
anaphylaxis
sepsis
R-sided HF
pericardial effusion
how do you answer the question “is there pericardial effusion?”? specifically in dogs and in abdominal US
look at subxiphoid (angle probe cranially a bit) and R parasternal sites
if there is pericardial effusion, there will be black space around the heart (which is beating)
if there is no pericardial effusion, then you’ll see a beating structure right by the liver (heart is touching diaphragm)
how do you answer the question “is there pleural effusion?”? with abdominal US
subxiphoid site (angle probe cranially a bit)
the diaphragm is touching the liver and lungs. If there’s a big black space between the diagraphm and lungs (along the diaphragm), then there’s pleural effusion
there will be NO mirror image artifact of the liver
what is the “mirror image” artifact?
when US hits air, a mirror image of the other tissue gets radiated back. so when you’re at the subxiphoid space and assessing if there’s pleural effusion, if you see a mirror image of the liver, that means there’s air on the other side of the diaphragm (lungs), and that’s normal!
what are the 2 enemies of ultrasound?
bone
air
Tell me the monographically definable borders of the lung
Caudal –> curtain sign
Cranial –> shoulder flexor mm + thoracic inlet
Dorsal –> hypaxial/sublumbar
Ventral –> ventral pleural border, ventral lung border
How do you find the pleural line on US?
bat sign
US waves can’t go through bone or air, so when you place the probe transthoracially, you get a bat sign:
brighter thin white line in middle = pleural line
two little white bumps on either side = rib heads
black space under rib heads = rib shadows
space under pleural line = artifact
How do you identify if the lung pleura are normal?
glide sign + bat sign
parietal and visceral pleura can’t be distinguished on US and so form a single line = pleural line
the parietal pleura slides against the visceral pleura in opposite directions, which creates a horizontal “shimmer” = glide sign
